Root ectomycorrhizal status of oak trees symptomatic and asymptomatic for Acute Oak Decline in southern Britain
Root ectomycorrhizal status of oak trees symptomatic and asymptomatic for Acute Oak Decline in southern Britain
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DOI：
10.1016/j.foreco.2020.118800
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发表时间：
2021-02
影响因子：
3.7
通讯作者：
N. Barsoum;S. A'Hara;J. Cottrell;J. Forster;Mateo San Jose Garcia;K. Schonrogge;L. Shaw
中科院分区：
文献类型：
--
作者：
N. Barsoum;S. A'Hara;J. Cottrell;J. Forster;Mateo San Jose Garcia;K. Schonrogge;L. Shaw
急性橡树衰退症(AOD)是一种衰退性疾病，具有独特的症状，对橡树构成严重威胁。我们对AOD的原因的了解仍然很差，但很可能是多种生物和非生物因素导致了橡树状况的恶化。有证据表明，地上树木健康状况的迹象往往反映在地下的根和相关的外生菌根(ECM)真菌群落。然而，还没有研究探索这些潜在的关系，特别是在受AOD影响的树木中。在这项研究中，我们比较了英格兰南部三个以橡树为主的林地中与AOD症状橡树和AOD无症状树相关的ECM群落的功能探索类型的组成和范围。此外，我们还评估了AOD症状树和无症状树下表层土壤中细小根尖的丰度，并考虑了土壤对ECM群落的物理化学影响。在所研究的三个林地中，有两个林地的细根尖在无症状树上的出现频率显著高于有症状树，远距离ECM探测类型与无症状树的AOD呈弱正相关。然而，ECM的多样性和组成不受树木症状状态的影响，也与细根尖出现的频率无关。只有不同林地间的ECM多样性和组成(但不是勘探类型)差异明显，这与少数土壤化学变量有关。这项研究揭示了AOD的地上症状(即茎病变和大麦出口洞)与活根尖频率之间的关系，为衰退树木提供了一种潜在的额外诊断工具，并强调了考虑地下根际微生物群落的重要性。
Acute Oak Decline (AOD) is a decline-disease that has distinctive symptoms and poses a serious threat to oak. Our understanding of the causal factors of AOD remains poor but it is likely that multiple biotic and abiotic factors contribute to a deterioration in oak condition. There is evidence that indications of above-ground tree health status are frequently reflected below-ground in roots and associated ectomycorrhizal (ECM) fungal communities. However, no study has yet explored these potential relationships specifically in AOD affected trees. In this study, we compare the composition and range of functional exploration types of ECM communities associated with AOD symptomatic oak trees and with AOD asymptomatic trees in three oak-dominated woodlands in southern England. We additionally assess the abundance of fine root tips in surface soils beneath AOD symptomatic and asymptomatic trees and consider soil physico-chemical effects on ECM communities. The frequency of fine root tips was found to be significantly higher on asymptomatic compared with symptomatic trees in two of the three woodlands studied and long-distance ECM exploration types had a weak positive association with AOD asymptomatic trees. ECM diversity and composition were, however, unaffected by tree symptom status and were not related to the frequency of fine root tips. ECM diversity and compositional (but not exploration type) differences were evident only between the different woodlands and this was related to a small number of soil chemistry variables. This study revealed a relationship between the above-ground symptoms of AOD (i.e. stem lesions andAgrilus biguttatusexit holes) and the frequency of live root tips, providing a potential additional diagnostic tool of trees in decline and highlighting the importance of considering belowground rhizosphere microbiome communities..